Air Filter

According to the Environmental Protection Agency, indoor air can be up to 100 times more polluted than outdoor air, and since we spend as much as 90 percent of our time indoors, the quality of the air in our homes and offices can significantly affect the quality of our lives and the quality of our health.

Heating, ventilation and air conditioning (HVAC) units can have an impact on indoor air quality. More than 70 percent of American households have central heating and air conditioning units, but nearly half of homeowners do not consistently change their air filters. Air filters are designed to remove polluting particles such as pollen, dust and mold from the air, but over time, those particles accumulate and eventually restrict air flow. As a result, a saturated air filter contributes to a decrease in HVAC efficiency and becomes its own source of air pollution. Regular air filter maintenance is one of the simplest, most inexpensive and most effective means to improve both the efficiency of an HVAC and the quality of indoor air.

The common blue or green spun fiberglass air filters are considered the “traditional” filters, but they may not be as efficient at cleaning the air as other filters.

When choosing and caring for air filters, there are several features to consider.


Generally, air filters are one inch to four inches in depth, and they are available in a variety of heights and widths. An air filter is usually labeled based on its nominal size, which is the size of the filter rounded up to the nearest inch. An air filter should fit snugly into its chamber and be equipped with a sturdy frame for proper air filtration. Consult your HVAC owner manual for manufacturer-recommended specifications.


There are several types of air filters that are commonly used for residential HVAC systems. Spun fiberglass air filters may be considered the “traditional” air filters. They are inexpensive, disposable and effective at capturing common air pollutants, but they should be replaced at least monthly for proper air filtration. Pleated air filters are a more efficient choice since they collect minute pollutants and require replacement about every three months. They are also disposable, but they are slightly more expensive than their spun fiberglass counterparts. Some filters feature an electrostatic charge to attract more polluting particles, and some filters feature an antimicrobial treatment to prevent pollutants from living on the filter where they are trapped. Washable air filters can be reused and require replacement only every few years, so they can reduce waste. However, they are not disposable and therefore must be cleaned regularly. Consult your HVAC owner manual for manufacturer-recommended specifications.


Many air filter manufacturers and retailers use their own systems to evaluate a filter’s ability to remove polluting particles from the air. But, the Minimum Efficiency Reporting Value (MERV) of the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) is the only universal rating system for air filters. Residential air filters have MERV ratings of one to 12, depending on their abilities to capture miniscule particles. Most air filters remove large particles such as pollen, dust and lint quite adeptly, but filters with higher MERV ratings are more efficient and can capture microscopic mold spores, dust mite debris, pet dander, smoke, smog and even particles that carry viruses and odors. So, a higher MERV rating generally translates into cleaner air. Filters with higher MERV ratings also have to be replaced less often. ASHRAE recommends a filter with a MERV rating of at least six for most residences, but a filter with a nine to 12 MERV rating is considered the best choice, especially for households with people with allergies, asthma and other respiratory concerns. However, a filter with a MERV rating above 16 is not often recommended for residential filtration because it can actually restrict air flow, cause damage to HVAC systems and increase utility costs.


Some air filters, such as those made from spun fiberglass, have no pleating. Others are pleated. If you choose a pleated version, choose a filter with more pleats per foot, which has more filter media for cleaner, more efficient air flow.

Remember: every disposable air filter needs to be replaced at least every one to three months to maintain proper HVAC operation and to improve air quality. Washable air filters must be cleaned regularly, too. A filter may require replacement or maintenance more often if a member of the household smokes, if a member of the household suffers from respiratory concerns, if the home is located in a dusty or polluted area, or if the filter becomes saturated with polluting particles, especially at certain times of the year such as pollen season.



Environmental Protection Agency – Indoor Air Quality

A “Hole” Lot You May Not Know About Ozone

Earth is the only planet in our solar system that supports human life for a variety of reasons: the temperance of the climate, the availability of water, the presence of gravity. Our unique ozone layer is also vital to our existence on the third rock from the Sun. We have all heard of the hole in the ozone layer, but are we truly aware of the causes of ozone degradation and the steps we can take to protect this important element of our atmosphere?


Ozone (O3) is an unstable molecule comprised of three oxygen atoms. Depending on where it occurs, ozone can be both detrimental and beneficial.

Tropospheric ozone, which occurs in the lower levels of the Earth’s atmosphere, is a greenhouse gas and a pollutant caused by industrial and natural processes, and it is one of the main components of smog. Stratospheric ozone, however, exists in the upper levels of the Earth’s atmosphere and absorbs 93 to 99 percent of ultraviolet (UV) rays from the sun, which are potentially damaging to life on Earth.

This important part of our atmosphere, or what is commonly called the ozone layer, is in danger, though. The hole in the ozone layer refers to a significant thinning of stratospheric ozone discovered over Antarctica in 1985. However, the depletion of stratospheric ozone is a continuing, worldwide concern.

Ozone Layer


Substances known as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are major causes of stratospheric ozone depletion. CFCs and HCFCs have been widely used as refrigerants, insulators, adhesives, propellants and solvents. Other common ozone depleting chemicals include methyl bromide (a substance used in pesticides), halon (a substance used in fire extinguishers), tetrachloromethane (a substance used in pharmaceutical manufacturing) and methyl chloroform (an industrial solvent).

These chemicals contain chlorine atoms that destroy ozone molecules. In fact, one chlorine atom can destroy more than 100,000 ozone molecules.


Diminished amounts of stratospheric ozone allow more radiation from the sun to reach the Earth’s surface, and in turn, increased amounts of radiation have adverse effects on public health, fiscal resources and the environment. Prolonged exposure to UV rays can cause sunburn, cataracts, a weakened immune system and cancer – all of which lead to greater medical expenses. An increase in the presence of UV radiation can also lead to reduced crop yields and disruptions in the marine food chain, causing a loss of revenue and decreased food production. In addition, the depletion of stratospheric ozone alters the temperature distribution in the atmosphere and may contribute to cumulative climate change.


Measures have been pursued nationally and internationally to regulate damaging chlorine-based chemicals. Ratified by all members of The United Nations, the Montreal Protocol on Substances That Deplete the Ozone Layer was introduced in 1987 and was designed to reduce the production and consumption of ozone depleting substances. Considered to be one of the most successful environment protection agreements in the world, the Montreal Protocol specifically addresses the CFCs and HCFCs that significantly contribute to ozone degradation, and it contains phase-out management plans.

Since the Montreal Protocol has been in effect, atmospheric concentrations of the most potent CFCs and related chlorinated chemicals have either stagnated or decreased. Halon concentrations are expected to decrease by 2020 as existing stores of the chemical are eventually eliminated. The presence of HCFCs has actually increased because these chemicals are used as alternatives to banned CFCs in solvents and refrigerating agents, but the Montreal Protocol calls for the elimination of HCFCs by 2030. According to the 2006 Scientific Assessment of Ozone Depletion, compliance with the Montreal Protocol has been excellent, and there is “clear evidence of a decrease in the atmospheric burden of ozone depleting substances and some early signs of stratospheric ozone recovery.”

Hydrofluorocarbons (HFCs) will ultimately replace CFCs and HCFCs. Unlike CFCs and HCFCs, HFCs do not contain chlorine and therefore have no ozone depletion potential.


If we curtail the production and use of ozone depleting substances, stratospheric ozone that is created through natural processes should restore the ozone layer by 2050.

To prevent pollution from detrimental tropospheric ozone and to prevent the degradation of beneficial stratospheric ozone, you can be more conscious of your use of ozone depleting substances.

– Properly maintain heating, ventilation and air conditioning systems (HVACs). Immediately repair any leaks. Coolants can often contain ozone depleting substances.

– Ensure that CFCs, HCFCs, halons and related substances are properly captured and recycled. Emissions from existing banks of chlorinated chemicals are not regulated under the Montreal Protocol and could still pose a threat to the ozone layer.

– When replacing your air conditioning system, consider a model that does not contain CFCs or HCFCs.

– Replace halon fire extinguishers with carbon dioxide or foam alternatives if possible.

– Reduce your energy consumption.

– Avoid the use of products that contain volatile organic compounds, CFCs, HCFCs and other ozone depleting substances to reduce impacts on the ozone layer and improve air quality. Visit the Environmental Protection Agency – Ozone Depleting Substances for a list.

September 16 is International Day for Preservation of the Ozone Layer. Learn more at The United Nations.

Do Your Share to Care for the Air

Air is essential for life, and yet, the quality of this vital natural resource is constantly threatened by numerous sources of pollution. The quality of air in the United States has significantly improved since regulations such as the Clean Air Act were imposed to protect our health and our environment. However, millions of people in the United States still live in areas with unhealthy levels of air pollution. Do your share to care for the air and to improve the quality of your life!


– Know your air quality forecast and heed the voluntary recommendations on Ozone Action Days. Local municipalities, cities or states can declare an Ozone Action Day when weather conditions and pollution levels can lead to health concerns. Air quality forecasts are available at

– Reduce your consumption of energy. Power generation is energy intensive, and power plants that produce energy often emit pollutants such as arsenic, mercury, heavy metals and acidic gases into the environment. These pollutants can degrade air quality and present associated health concerns such as allergies and respiratory issues.

– Recycle. The production of goods from recycled materials requires less energy and emits fewer pollutants than the production of goods from new materials. Last year, nearly 200 million metric tons of carbon emissions were avoided by recycling – the equivalent of removing 33 million cars from the road.

– Drive less by carpooling with your colleagues, chaining your trips, walking to your destination, cycling to your destination or using mass transit if possible.

– Fill your gasoline tank during evening hours to reduce vapor evaporation. Gasoline vapors contain air pollutants such as benzene.

– Do not top off your gasoline tank. If you do, you can release gasoline vapors into the air. Also, many gasoline stations have vapor recovery systems that prevent vapor evaporation. Any gasoline pumped following the engagement of the fuel capacity sensor will be drawn into the vapor recovery system and returned to the station’s storage tanks. So, by topping off your tank, you are essentially wasting fiscal resources and harming natural resources.

– Practice regular vehicle maintenance to ensure that your emissions system is functioning properly and to sustain optimal fuel efficiency.

– Avoid the use of gasoline powered equipment on Ozone Action Days.

– Do not burn trash! The burning of trash – both open burn methods and burn barrel methods – is prohibited in North Carolina. Place garbage in an appropriate container. The burning of vegetation is also prohibited in areas where municipal vegetation collection is available. Burning for occasions such as barbecues is allowed under certain circumstances but should be conducted only in accordance with North Carolina Fire Codes and Fort Bragg regulations. If you live on Fort Bragg, contact Corvias Military Living for policies pertaining to post residents. All burning should be avoided on Ozone Action Days. Visit for information.

– Use environmentally preferred, biobased and biodegradable products that contain no or minimal volatile organic compounds, or VOCs. VOCs such as formaldehyde, toluene and perchloroethylene can contribute to degraded air quality and cause associated health concerns.

– Use propane instead of charcoal for grilling. According to the Department of Energy, a propane grill produces 5.6 pounds of carbon emissions during each hour of use whereas a charcoal grill produces 11 pounds of carbon emissions during each hour of use when production, transportation and burning are all considered.



North Carolina Department of Environment and Natural Resources Division of Air Quality

Environmental Protection Agency Air Quality Planning and Standards

American Lung Association State of the Air

Green Grilling

This Memorial Day, will you fire up your grill? If hosting a barbecue is in your plans this season, you are among the 75 percent of American homes that own at least one grill and one of the 60 million Americans who will use a grill during the summer holidays. However, you are also contributing to the 225,000 metric tons of carbon dioxide released during these celebrations. No need to bar the ‘cue from your party, though. Grilling can be fun, healthy and sustainable throughout the summer with some simple considerations.

Grilled Chicken

Propane, natural gas and charcoal all have their benefits and disadvantages.
In terms of derivation, propane and natural gas are non-renewable resources whereas charcoal is a renewable resource. Propane and natural gas are fossil fuels derived from an accumulation of remains of organic matter. On the other hand, charcoal is a bio-fuel produced by burning a carbon based material such as wood.
The manufacturing processes used to extract these materials from their natural states are all energy intensive, and they also have many environmental impacts. Propane and natural gas are extracted by methods which can create pollution and disrupt natural habitats. The production of charcoal, though, emits a myriad of carcinogenic industrial chemicals including methanol and acetone. Whereas charcoal briquettes are recycled from waste wood and sawdust, many commercial varieties also contain substances such as nitrate accelerants, binding agents and ash whitening agents that can leach into food. Natural lump charcoal is manufactured from new wood and can contribute to deforestation if the sources are improperly managed, but it usually contains fewer additives.
Emissions are another consideration for these fuels. Propane and natural gas burn cleaner than charcoal. According to the Environmental Protection Agency, charcoal briquettes are the most common form of charcoal used on home grills, but they release 105 times more carbon monoxide than propane. An Environmental Impact Assessment Review conducted in Britain discovered that a charcoal grill emits 2,200 pounds of carbon dioxide in its life whereas a natural gas grill emits 769 pounds of carbon dioxide in its life. Self-lighting charcoal and the lighter fluids used to ignite charcoal fires also release volatile organic compounds into the air when they are burned. Each year, Americans burn 46,000 tons of lighter fluid that send over 14,000 tons of VOCs into the atmosphere.
Furthermore, waste can be a concern when selecting propane, natural gas or charcoal. Propane and natural gas generate no waste because their receptacles can be reused or recycled. Charcoal creates waste that must be properly handled to prevent residual fire.
Ultimately, propane and natural gas are more environmentally sound than charcoal. If you prefer to use charcoal, however, the most sustainable option is natural lump charcoal that is made from certified, sustainably harvested wood and contains no chemical additives. Charcoal chimneys, electric charcoal starters and natural combustion agents such as fat wood are environmentally preferred alternatives to lighter fluid.

• Send invitations to your barbecue electronically to reduce paper waste.
• Encourage your guests to carpool, use mass transit, cycle or walk to your barbecue.
• Use locally harvested foods for your barbecue.
• Use reusable dishes instead of disposable options. If you must use disposable items, choose compostable or recyclable products. Avoid Styrofoam.
• Avoid single serving products to reduce waste created by excess packaging.
• Buy products in recyclable or reusable containers.
• Use your grill only in well-ventilated areas. If they are not used properly, grills can emit high levels of carbon monoxide, a poisonous gas.
• Extinguish your grill completely to prevent residual fires that can damage property and the natural environment.
• Clean your grill with natural, biobased cleansers to prevent the transfer of chemicals from the grill to your food.
• Always place litter in an appropriate container.
• Recycle as much as possible.
• Send food home with your guests.


Green Grilling

For further reading, visit The Tree Hugger How to Go Green Guide for Barbecues.

The Air Quality Forecast: A User’s Guide

As summer approaches and the temperature rises, the presence of air pollutants and the health concerns associated with those pollutants increase as well. You can protect your health with an understanding of the Air Quality Forecast. The Environmental Protection Agency (EPA) calculates the Air Quality Forecast daily in accordance with the Clean Air Act. The forecast provides several pieces of information.
• A range of air quality values, or the Air Quality Index (AQI).
• The levels of pollutants present in the air
• The health concerns associated with those values and pollutants
• The demographic groups who are most susceptible to those health concerns
• The recommended actions necessary to sustain health

What Color is Your Air
The AQI ranges from 0 to 500, with 0 indicating the healthiest air quality and 500 indicating the unhealthiest air quality.
The Air Quality Forecast covers six common air pollutants: ground level ozone, particle pollution, carbon monoxide, sulfur dioxide, nitrogen dioxide and lead. Ground level ozone forms when pollutants from vehicles, industrial activities, volatile organic compounds and other sources combine in the heat. Ozone levels peak in the hours between the early afternoon and the early evening during the summer. Particle pollution is a combination of small solids and liquids suspended in the air. Particle pollution can peak at any time. Carbon monoxide, sulfur dioxide and nitrogen dioxide are all harmful gases. Lead is a heavy metal that can be emitted into the atmosphere most often through dust and fuel vapors. These pollutants are the primary components of the environmental phenomena known as smog and acid rain.
The pollutants present in unhealthy air can cause or worsen respiratory issues such as asthma, allergies, eye irritation, skin irritation and even cardiovascular concerns. They can also degrade the immune system and cause vulnerability to infection.
The demographic groups who are most susceptible to the negative impacts of polluted air include children, active individuals, elderly adults and individuals with heart or lung conditions. Children breathe at a higher respiratory rate than adults, so they are more prone to ingest pollutants. Furthermore, their developing lungs are more sensitive to the effects of these pollutants. Active individuals often participate in activities that require physical exertion, so they are also more prone to ingest air pollutants as a result of their higher respiratory rates. Older adults have less resistance to ambient air pollutants, and they are more vulnerable to heart and lung conditions. Individuals with heart conditions such as coronary artery disease and congestive heart failure or lung conditions such as asthma and emphysema often have weakened immune systems and respiratory issues that can be exacerbated by polluted air.
Depending on the levels of pollutants in the air, the Air Quality Forecast also recommends actions for sustaining health. These recommendations range from no action on days when the air quality is healthy to a complete avoidance of all physical exertion on days when the air quality is unhealthy.
The Air Quality Forecast is color coded.
Code Green indicates air quality in the range of 0 to 50 on the AQI, or air that is healthy. All demographic groups can participate in their normal activities, as air quality forecasters do not anticipate an increase in health concerns caused by air pollution.
Code Yellow indicates air quality in the range of 51 to 100 on the AQI, or air that is moderately healthy. Unusually sensitive individuals may experience the effects of air quality at this level and should consider limiting prolonged exposure or exertion.
Code Orange indicates air quality in the range of 101 to 150 on the AQI, or air that is unhealthy for sensitive groups. Children, active individuals, elderly adults and individuals with heart or lung conditions should limit prolonged exposure or exertion.
Code Red indicates air quality in the range of 151 to 200 on the AQI, or air that is unhealthy for all groups. Children, active individuals, elderly adults and individuals with heart or lung conditions should avoid exposure or exertion. All other groups should limit prolonged exposure or exertion.
Code Purple indicates air quality in the range of 201 to 300 on the AQI, or air that is very unhealthy for all groups. All individuals should avoid exposure and exertion until Code Purple conditions are lifted.
Code Burgundy indicates air quality in the range of 300 to 501 on the AQI, or air that is hazardous. If air quality is in this range, the entire population may experience adverse effects from air pollutants regardless of exposure level. Code Burgundy conditions require emergency action.
The Internet resource AIRNow is a partnership between the EPA, the National Oceanic and Atmospheric Administration, the National Parks Service and variety of agencies at federal, state, regional and local levels. The site provides air quality forecasts for over 300 major United States cities and maps indicating air quality conditions throughout the nation.
The AIRNow mobile app for your Android or iPhone provides location specific reports on air quality information as well as forecasts for both ozone and particle pollution.
The Division of Air Quality of the North Carolina Department of Environment and Natural Resources provides air quality forecasts and information specific to the state.

To contact the Fort Bragg Air Quality Program Manager, please call Gary Cullen at 432.8464.